The proposed Mentored Research Scientist Development Award (K01) is a 5-year plan for Rachel Marsh, Ph.D. to develop into an independent investigator of the neural systems that mediate self-regulatory control processes and habit learning in childhood psychopathologies. Advancing our understanding of abnormalities in these systems may shed light on the pathophysiology and pathogenesis of disorders in which children and adolescents are plagued by the presence of impulsive and habitual behaviors. This application requests support for a career development and research plan to study self-regulatory control processes and habit learning in adolescents with Bulimia Nervosa (BN). The career development activities build on Dr. Marsh's background in developmental and experimental psychology and capitalize on the resources at Columbia University to allow her to achieve her long-term goal of becoming an independent investigator of childhood psychopathologies. These activities integrate both formal didactic experience and hands-on practicum that will enable her to: (1) develop expertise in functional neuroimaging techniques;(2) acquire more comprehensive knowledge of basic and cognitive neuroscience;(3) increase her understanding of the clinical phenotypes and pathophysiology of childhood disorders;and (4) gain clinical experience in the assessment of BN and expertise in its pathophysiology. Complementing these training activities, Dr. Marsh proposes to use fMRI to identify functional impairments of frontostriatal circuitry, the primary mediator of self- regulatory control, in adolescents with BN that may predict the presence or perpetuation of the disorder. The proposed research will also help to define the functional characteristics of habit-learning systems within the basal ganglia that may be abnormal in adolescents with BN and contribute to their habitual binging and purging behaviors. Disturbances in frontstriatal systems may release the underlying vulnerabilities to develop BN from regulatory control, contributing to the expression of these habitual behaviors. Findings from this study will have wide-ranging importance for the understanding of the development and treatment of BN and help to define the role of self-regulatory control and habit-learning systems in other pathological conditions that originate in childhood.